Dowel pin extraction tools are known in the art and are useful for extracting headless pins that are press mounted in blind holes provided through the mounting surface of tooling plates on drilling machines, milling machines, Computed Numerical Control (or CNC) machine tools, multi-part injection molds, and the likes.
Some examples of the prior art are U.S. Pat. Application No. US2003/0140473, to Martantette (published in July 2003), U.S. Pat. No. 5,604,967, to McMahon (issued In February 1997), U.S. Pat. No. 5,193,260, to Pierce (issued in March 1993), U.S. Pat. No. 5,075,948, to Maier (issued in December 1991), U.S. Pat. No. 4,263,705, to Devening (issued in April 1981), and U.S. Pat. No. 3,750,500, to Peterson (issued in August 1973).
While these prior art devices offer an extraction tool that can extract dowel pins from mounting plates and injection molds, they also entail one or more of the following disadvantages:
a) they are generally designed for extracting dowel pins having a specific diameter size;
b) for other implementations of an extraction tool of the prior art that are adapted to extract dowel pins having different diameter sizes, a set of modular parts for the tool must be kept close at hand and exchanged when required;
c) still other implementations of an extraction tool adapted to extract dowel pins having differently sized diameters, are generally provided with a pair of adjustable gripping jaws, much like the gripping jaws on a pair of pliers or a vise, which often damage the cylindrical surface of the dowel pin and/or the adjacent planar surface of the mounting plate;
d) the extraction tools of the prior art that are provided with a means for pushing against the mounting plate, in order to pull the dowel pin out of a blind hole, have their gripping or clamping means axially constrained relative to the pushing means, which creates oblique forces between the extraction tool, the dowel pin and the mounting plate which, in turn, is often a cause of damage to the dowel pin and/or the mounting plate.
Against this background, there exist a need for an improved pin extraction tool. An object of this invention is to provide such a pin extraction tool.